Composition containing colloidal methyl ether of methylol melamine and other thermoplastic resins and process of applying to cellulose textiles



Patented Dec. 1, 1953 UNITED STATES ATENT OFFICE COMPOSITION CONTAININGCOLLOIDAL METHYL ETHER F METHYLOL MEL- AMINE AND OTHER THERMOPLASTICRESINS AND PROCESS OF APPLYING T0 CELLUIJOSE TEXTILES corporation ofDelaware No Drawing. Application January 30, 1950, Serial No. 141,353

14 Claims. :1

The present invention relates to the treatment .of fabrics containingcellulosic yarns or filaments for the purposes,:among others, ofimproving their dimensional stability and producing durablestiffenedfinishes.

It'has been proposed hieretofore'to treat fabrics containingcellulosi'ciyarns with'starch solutions to provide a fabric having arelatively stiffened finish. Starched fabrics however, lose theirstiffness after a single laundering and alsotend to "dust out. Moreover,starch does not improve the dimensionalstability'of the fabric.

It has also been -proposed heretofore to treat cellulosic fabrics withurea-formaldehyde condensation products or melamine-formaldehydecondensation products 'for :the purpose of in proving the crease orcrush resistance and the dimensional stability of "the fabrics.Such'trea'tmerits, however, "provide a fabric which has a rather softand full hand, which property'is objectionable or undesirable forcertain fabric uses. Moreover, such treatments often-cause a-marked lossin tensile strength of the fabric.

In accordance with the present invention it is possible to treat fabricscontaining cellulosic yarns or filaments with relatively small amountsof a'p'otentially resinous substance which can be insolubilized atrelatively low temperatures to provide fabrics having improveddimensional s'ta'bility and a crisp, permanently stiffenedfinish,without'appreciable loss in tensile strength. It is also possiblein accordance with this invention'to fix on fabrics dyestuffs whichnormally bleed in hot water.

It-is accordingly one object of this invention to provide improvedmethods of finishing textile fabrics containing cellulosic yarns or"filaments.

A further object of this invention is to treat fabrics containingcellulosic yarns with relatively small amounts of a potentially resinous:substance, which is capable of being insolubilized atrelatively'lowtemperatures, for the purpose of providing a fabric having a crisp,permanently stiffened finish and improved dimensional'stability, andgood tensile strength.

Still further objects an'dadvantages of this invention will appear inthe following description and the appended claims.

The processes of this invention are carried out, in general, by firsttreating a fabric containing cellulosic yarns such-as cotton yarns orregenerated cellulose yarns with an acidic aqueous colloidal solution'ofa partially polymerized methylated melamine formal'dehyde or methylether of 'methylormelamine condensation prodnot having a mol ratio ofcombined formaldehyde to melamine of. at least:2;8 tol, the amount ofthe solution supplied and the concentration thereof being so adjusted.as to :deposit :from about 1 to 12% by weight'of the condensationproduct, based on :the weight of fabric. It :is preferred, however, todeposit tfrom.2 to .9% my weight of the condensation product, based ionthe weight of the'fabric.

After the condensationproduct has beenapplied to the fabric, thefabricis dried andfthen heated to insolubilize the-condensation:productor the fabric is heated to *dry the fabric and insolubilize thecondensation productinroneoperation. In some :instances andv-=particular1y when the condensation product *is exhausted onto thefabric, as will ibe described in greater detail hereinafter, it :is notnecessary to J'heat the fabric to insolubilize the :condensatiomprodnotand in such casesdryingofttheifabric:isz'sufficient. Satisfactoryinsoiubilization of the icondensation product is obtained by heating"the fabric at temperatures of .225 to 300F. However, in some instances,lower temperatures, ffor example, 200 F. may be used if "the :fabric' isheated for sufficiently long periods-of time, for higher temperatures,for example, 350 :F. :may be used when shorter heating'periodssare-.-desirable. In general, at the.aboveedescribed temperatures thecondensation .product is :insolubilized within a period of 3to.20:minutes,ithe shorter heating period corresponding Zto the highertemperatures.

A particularly suitable procedure for :treating the fabric comprisesthesteps of 'first'wetting out the fabric in an acidic aqueous colloidalsolution containing from l'to 12% by weight of'the partially polymerizedcondensation .product. This is done by wayofexampleyby immersing ordipping the fabrics in thesolution or {by spraying the solution on .thefabric until the fabric is thoroughly wetted out or saturated with thesolution. The fabric is then extracted-that is, excess solution issqueezed out 'o'f thefabric as, for example, by wringing orcentrifuging-the fabric, or by passing the fabric-'betweennsqueezerolls, the degree of extraction-beingno adiusted as to deposit from 1 to12%,zpreferably2 (309%, by weight of the condensationxproduct, based onthe initial fabric weight.

A preferred procedure-consists in passing -'the fabric through theyacidic aqueous colloidal solution of the partially polymerizedacondensation product in such amanner thatgthe fabric isa-immersed belowthe surface :of-rthesolution and Lie thus wetted out, after which thefabric is passed between squeeze rolls to remove excess solution. Thisprocedure is preferred because it gives the best results and insureseconomical wetting out of the fabric. This procedure also provides acrisp, durable or permanent finish after the condensation product isinsolubilized. After the condensation product is applied to the fabric,the fabric is then dried and the condensation product is insolubilizedthereon as described above. Since the solution applied to the fabric isacidic and acids tend to tender or weaken cellulosic materials, it isessential to wash the fabric, after the condensation product has beeninsolubilized, to remove the acid left in the fabric. The fabric is thendried.

The treatment described herein is carried out on dyed fabrics or onundyed fabrics. It is preferable to treat a dyed fabric since it is thuspossible to obtain good dye fixation in addition to shrinkage control ordimensional stability, and a durable stiffened finish. The fabricsemployed in this invention preferably consist of yarns of naturalcellulose such as cotton, linen, etc. or yarns of regenerated cellulose,for example, viscose and cuprammonium rayon, or mixtures thereof.However, it is possible to treat fabrics containing other types of yarnsand at least 70% of yarns of natural or regenerated cellulose ormixtures thereof. The term yarns is intended to cover yarns preparedfrom fibers of natural cellulose or staple fibers of regeneratedcellulose and is also intended to cover continuous regenerated cellulosefilaments. The term cellulosic is intended to cover natural orregenerated cellulose materials to the exclusion of other forms ofcellulose. Particularly suitable fabrics for treatment according to thisinvention are cotton or viscose rayon marquisettes and other cellulosicfabrics which when treated with the colloidal solutions provides,lawn-type finish.

The colloidal solutions employed herein may be prepared in a variety ofways. One suitable method of preparation consists of first forming anaqueous solution of a water-soluble infinitely dilutable methyl ether ofmethylol melamine condensation product having a pH between '7 and 11 andcontaining at least 3.4 mols of combined formaldehyde and preferably atleast 2 mols of combined methanol for each mol of melamine in thecondensation product. The term infinitely dilutable is intended to covercondensation products having a degree of polymerization such that 1 partof a 30% by weight solution of the condensation product can be dilutedwith 100 parts of water without precipitating the condensation product.The solution of the condensation product is mixed with a water-solubleorganic acid selected from the group consisting of acetic acid, hydroxyacetic acid and formic acid, and water, if required, to form a solutioncontaining from 6 to 12% by weight of the condensation product. Theamount of acid required to form the colloidal solution is primarilydependent on the concentration of condensation product in the solutionand the particular species of acid used. Satisfactory colloidalsolutions are formed, for example, by using from 6 to 8.5% by weight ofacetic acid calculated on the basis of a by weight solution of thecondensation product, or by using the same amounts of hydroxyacetic(glycollic) acid instead of acetic acid, or by using from 1.2 to 3% byweight of formic acid calculated on the basis of a 10% by weightsolution of the condensation product. Mixtures of such acids may also beused. The proportions of acid used thus fall within the range of about1.2 to 8.5% by weight of the acid calculated on the basis of a 10% byweight solution of the condensation product, the particular amount ofacid used being dependent on the particular species of acid employed.

Acetic acid is the cheapest of the useful organic acids and the mostsuitable for preparing the colloidal solutions and for application tocellulosic fabrics. It is therefore preferred for use in preparing thecolloidal solutions of the condensation product. When acetic acid isemployed for this purpose, it is preferred to use from 6.5 to 8% byweight of acetic acid calculated on the basis of a 10% by weightsolution of the condensation product. When hydroxyacetic acid isemployed, it is preferred to use from 7 to 8.5% by weight of such acidcalculated on the basis of a 10% by weight solution of the condensationproduct. When formic acid is employed it is preferred to use from 1.4 to2% by weight of such acid calculated on the basis of a 10% solution ofthe condensation product.

After the acid has been added to the 6 to 12% by weight aqueous solutionof the condensation product, the resulting solution is aged at leastuntil the particles of condensation product contained therein polymerizesufficiently to attain colloidal size. The formation of the colloidalsolution is evidenced in part by a change in the appearance of theoriginal solution. The original solution is water clear but afterstanding at a temperature, for example, of '70 to F. for about 4 hoursit develops a bluish opalescence or haze and gives the characteristicTyndall effect of colloidal solutions. At these temperatures a 6 houraging period is generally suitable for developing colloidal sizedparticles under mill conditions.

The formation of the colloidal solution of the condensation product isfurther evidenced by the fact that the condensation product thereinbecomes substantive to cotton fibers, that is to say,

' the colloidal particles of the condensation product migrate from thesolution to cotton fibers, and in low concentrations will be almostcompletely adsorbed by the cotton fibers. This is in contrast to theoriginal neutral or alkaline solution of the condensation product or thesame solution which has been acidified but not aged since thecondensation product in either of these solutions is not substantive tocotton fibers. The substantivity of the colloidal particles to cottonfibers is also strong evidence that such particles are positivelycharged since it is generally believed that cotton fibers have anegative charge in the presence of water and thus attract positivelycharged particles.

The solutions of the condensation product may be applied to the fabricas soon as the particles therein attain colloidal size, which usuallyrequires an aging period of about 3 to 6 hours at temperatures of '70 to90 F. depending on the particular acid used, the amount of acid employedand the concentration of the condensation product in the solution. Ingeneral, the colloidal solutions are still suitable for use after agingfor 72 to 168 hours at such temperatures. The viscosity of the solutionis one criterion for determining its suitability after prolonged periodsof aging. For example, a 10% by weight colloidal solution of thecondensation product, after 4 to 6 hours of aging, has a viscosity ofabout 3 to 5 centipoises. The viscosity does not change to anyappreciable extemperatures of about 10 to 200" F., the colloidalsolution forms at a relatively rapid rate and the original solution maybe satisfactorily converted colloidal solution may becomeunfit for useduring the treatment of the fabric.

The aging temperature and exposure of the- -solution to air have amarked influence on the rate of formation of the colloidal solution andthe rate at which such solution finally converts to agel. Attemperatures below' 70 that is, between about 40F. and 70 F., thecolloidal-solutio'nforms-at a relatively slow rate'and the originalsolution may-require more than a '6 hour aging period before it isconverted to a colloidal solution. Attemperatures above 90F that is,

to a-colloi'dal solution Within a '3 hour agingperiod. Exposure of thecolloidal solutionto air decreases the time period within which thecolloidal solution will be stable to gelation. In general, an -agingperiod of 3 *to "72 hours is "suitable "for the "preparation of thecolloidal'solution using the aging temperatures described above. It ispreferred, howeveiflto' use an aging period of 6 to 30 hours.

The condensation product in the colloidal solution is characterized bythe 'fact that it contains at least 2.8 mols of combined formaldehydefor each mol of melamine therein. Theratio'o'f combined formaldehyde tomelamine is higher than 2.8 to 1 in those instances'where the originalmethyl ether of methyl-o1 melamine condensation product contains from3.5 to dmolsof combined formaldehyde and more than 2.5 mols of combinedmethanol for each mol of melamine.

Methyl ethers containing 6 mols of combined formaldehyde and from 5 to 6mols of combined methanol may also be used to prepare'the 'col- -1oidalsolutions employed therein. However, such products are quite-expensiveto prepare. Moreover, they do not showranyadvantages and are not asstable in colloidal form, in most instances, as the lower methyl ethersdescribed above. 'Best results are obtained by-using colloidal solutionswhich are prepared from methyl ethers'of methylol melamine condensationproducts which contain originallyffrom 3.4 to5.5' mols of combinedformaldehydeand from 2to- 3 mols of combined methanol for each mol ofmelamine 'and these products are. accordingly, preferred.

The methyl ethers of methylol melamines employed in this invention arecommerciallyavailableproducts and maybe prepared in*various ways. -Asuitable method for their preparation consists in first reactingmelamine and formaldehyde, as formalin, in mol ratios of about lf3;5 to

:about 1:8 in an alkaline reacting solution ate temperature betweenabout 60 and 90 C. until the melamine is substantially dissolved. 'Themixture is made alkaline-reacting, for example, by the addition of fixedalkalis-suchas sodium'hyd oxide, soda ash or the like. Methanol is thenadded to this solution forthe-purpose of forming the methyl ether. InigeneraL from about 10 to 30 mols or more of methanol-are employedforeach mol of melamine used. The solution isthen acidifiedto apH'betweenabout 2 and'5 witha strong mineralacid such as-phosphoric'acid, hydrochloric acid and thelli-ke. "This mixture'is:heatedto atemperature between about and 60 C. until a homogeneoussolution is obtained and t-he condensation product contains .at least"314 mols of'comb'ine'd formaldehyde and'preferablyiat 5 -leastl2 molsof combined methanol for 'each'mol er melamine used. The reactionisdiscontinued, however, while the degree of polymerizationiis "suchthat the solution of "the condensationxprod- -1I-ctis still diluta-blewith large volumes of'water 'without precipitation of the condensationproduct. The solution of the condensation product, while it is still'dilutable with water,'-is then neutr-alized with afix'ed alkali suchas'KO-I-L 'NaOH, "Na'2CO3 and the like'and'then cooled. Precip- -itatedsalts formed by the neutralization of the excess mineral acid with th'efixed alkali: may b'e re'move'd, if desire'd, by filtering, centrifugingor -the like. The solution is now -ready'for-use'I-in the preparation ofthe colloidal solution 'Of 'tIi'e condensation product.

A further understanding of this invention will be obtained from thefollowing specific examples "which are intendedto further illustrate thelnventiom but not to "limit the scope thereof,'='parts 25 andpercentages being by weight unless otherwise specified.

Emample 'I -A. :-Preparation of a water'solutzoniojs iwater- 3 solublemethyl ether of 'methylolmelamina- One hundred and twenty-seven parts.(aboutl mol) :of melamine were mixed "with .365 parts of a37% "aqueoussolution of formaldehyde (4:5 mols HCHO) T The resulting mixture wasadjusted to a pH of 8.6 (glass electrode) with NaOH and t'hen trode)with NaOI-I. The resultingsolution was -then"concentrated by subjectingit'to avacuum 'o'f"1"0mil1im'eters ofmercury at a temperature of -60'"C.until it"containe'd 60% of the condensation "product. The solutionwas then cooled rapidly "to -20 C. 'The resulting solution wasinfinitely "dilutablewith water. The condensation product inthe'sblutionwasanalyzed and was Tfoundto contain3l5 mols of combined'formaldehy'deand "212 mols of combined methanol .for each .mol of melamine used.

B. "Preparation of acidic aqueous colloidal solution of methyl ether ofmethylol meZeamz'ne.--Two hundred and eightyparts of the solution, asprepared above, were-stirred together with 1186 co' rts f'water and2-l8-parts of 56% acetic acid.

The resulting solution contained about 10% of the methyl ether ofmethylol melamine condensationproduct and about 7.2% of acetic-acid andhad a pHof 3.9. The solution was allowed to age for 6 hours at 85 'F.Duringthis aging period had a pH of 317. The condensation product was'analyzed and contained 2.9 mols of combined formaldehyde for each mol ofmelamine.

C. Treatment of all cotton fabric.-One hundred an'deight'y parts of thecolloidal-solutionprepared as described in paragraph B above, wereproduct.

7 diluted with 120 parts of water. The resulting colloidal solutioncontained condensatmn A piece of cotton marquisette was wetted out inthis solution and then extracted by passing it between pad rollsadjusted to give a pick-up of 136% of solution on the weight of thefabric. About 8.3% of the condensation product based on the fabricweight was thus applied to the fabric. The fabric was dried at 180 F.and then heated for an additional 10 minutes at 250 F. to insolubilizethe condensation product. The fabric was next rinsed for 5 minutes inwater at a temperature of 110 F., secured for 10 minutes in a 0.1% watersolution of dodecyl benzene sodium sulfonate at a temperature of 110 F,and finally rinsed in water at 110 F. and dried.

The resulting fabric had excellent dimensional stability, that is,resistance to shrinkage and it also had a crisp, stiffened finish, bothof which properties were retained to a substantial degree after a numberof standard AATCC (American Association of Textile Colourists andChemists) cotton washes. Moreover, the treated fabric had substantiallythe same tensile strength as the untreated fabric from which it wasprepared.

Pieces of viscose rayon marquisette, cotton sheeting and viscose rayonfabric were treated in the same manner as the cotton marquisette, asdescribed in paragraph C above, with substantially the same results,that is, the treated fabrics exhibited excellent dimensional stabilityand a crisp, stiffened finish, both of which properties were notmaterially affected by a number of launderings, and without anyappreciable loss in tensile strength.

' Example II A. Preparation of acidic [aqueous colloidal solution ofmethyl ether of methylol melamine.--'I'wo hundred and eighty parts ofthe 60% solution prepared in accordance with paragraph A of Example Iwere stirred together with 122- parts of hydroxyacetic acid and 1282parts of water. The resulting solution contained about 10% of the methylether of methylol melamine condensation product and about 7.2% ofhydroxyacetic acid.

.The solution was allowed to age for 30 hours at a temperature of 80 F.At the end of the aging period the solution had a bluish opalescentappearance and the particles of partially polymerized condensationproduct were substantive to cotton fibers. The solution was analyzed andit was found that the condensation product therein comprised 2.9 mols ofcombined formaldehyde per mol of melamine.

.B. Treatment of all cotton fabric-The colloidal solution as preparedimmediately above was diluted with water until it contained 6% of thepartially polymerized condensation product. A cotton marquisette wasthen treated with this solution, dried, heated to insolubilize thecondensation product and washed, using the identical procedure describedin paragraph C of Example I.

The resulting fabric hadexcellent dimensional stability and it alsopossessed a crisp, stiffened finish. It also had substantially the sametensile strength as the untreated fabrics. The treated fabric hadexcellent resistance to shrinkage and retained its crisp, stiffenedfinish after a number of standard AATCC cotton washes.

Example III A. Preparation of acidic aqueous colloidal solution ofmethyl ether of methylol melamine.Two

substantive to cotton fibers.

hundred and eighty parts of the 60% solution prepared in accordance withparagraph A of Example I, were stirred together with 13'76 parts ofwater and 28 parts of formic acid. The resulting solution containedabout 10% of the methyl ether of methylol melamine condensation productand 1.6% formic acid and had a pH of 5.5. This solution was allowed toage for 6 hours at 85 F. After this aging period the solution had beenconverted to a colloidal solution having a bluish hazy appearance and aviscosity of 4 centipoises. The colloidal particles of partiallypolymerized condensation product were substantive to cotton fibers. Thiscolloid solution had a pH of 5.3. Analysis showed that the condensationproduct therein contained 2.95 mols of combined formaldehyde for eachmol of melamine.

B. Treatment of all cotton fabric-The colloidal solution as preparedimmediately above was diluted with water until it contained 6% of thepartially polymerized condensation product. A cotton marquisette wasthen treated with this solution, dried, heated to insolubilize theconden sation product and washed, using the identical proceduredescribed in paragraph C of Example I.

The resulting fabric had excellent dimensional stability and it alsopossessed a. crisp, stiffened finish. It also had substantially the sametensile strength as the untreated fabric. The treated fabric hadexcellent resistance to shrinkage and retained its crisp, stiffenedfinish after a number of standard AATCC cotton washes.

Ezrample IV tained about 10% of the methyl ether of methylol melaminecondensation product, about 1.8% of polyvinyl acetate solids and about7.2% of acetic acid. This solution was allowed to age for 6 hours at 85F. After this aging period the solu-- tion had been converted to acolloidal solution having a bluish opalescent appearance and theparticles of condensation product therein were This solution wasanalyzed and it was found that the condensationproduct therein comprised2.9 mols of combined formaldehyde per mol of melamine.

B. Treatment of all cotton fabric-Three hundred and sixty parts of thecolloidal solution as prepared immediately above were diluted with 240parts of water.- The resulting solution contained 6% condensationproduct and about 1.1%

A piece of cotton marsolution on the weight of the marquisette. About8.2% of the condensation product and 1.5% of the polyvinyl acetate werethereby deposited on the fabric. The fabric was dried at 180 F. and thenheated for an additional 10 minutes at 250 F. to insolubilize thecondensation product.

. The fabric was next rinsed for 5 minutes in water at- F., scoured for10 minutes in a 0.1%

water solution of dodecyl benzene sodium sulfonate at a temperature of110 F. and finally rinsed in water at 110 F.

The resulting fabric exhibited excellent re sistance to shrinkage onlaundering and; also possessed a stinened finish which was retainedafter a number of cotton washes. The finish was not as crisp as thefinish obtained by the procedure, described in Example I'but Wasstiiferand the fabricpossessed afuller hand.

Instead of acid-stable dispersions of polyvinyl acetate otheracid-stable solutions or dispersions.

of thermoplastic resins may be used inthe colloidal solutions of themethyl ether of methylol;

melamine to provide a finish of increasedstiif ness and fullness ofhand. As examples ofsuitable thermoplastic resins may be mentionedwater-soluble copolymers of vinyl acetate and maleic acid or maleicanhydride, polymethacrylic acid, polyacrylic acidor polyvinyl alcohol,or Water dispersions of polystyrene or the like. The amount ofthermoplastic resin added is preferably from about 14 to 30 ontheweight;

of the condensation product, but amounts as low as. 1% on the weight ofthev condensation product, some instances, as high as 40% on the weightof the condensation product may be used.

Example V A. Preparation of methyl ether of mcthylol melaminc-ne hundredand twenty-seven parts (about 1 mol) of melamine were mixed with- 485parts of a 37% aqueous solution of formaldehyde (6 mols ECHO). Theresulting mixture was adjusted to a-pll' of 8.5 (glass electrode) withNaOH' and then heated at a term perature of 70 C. until the melamine wassubcentrated by subjecting it toa vacuum of mil-..

limeters of mercuryat a temperature of 609C. untilit contained 56%condensation product; The solution was then cooled rapidly to 253 C; Itwas infinitely dilutablewith water. densation product in the solutionwas analyzerandiwas found to contain 5.3:mols of combined formaldehydeand 2.9.m01s of combined methanol foreach moi of melamine used.

B. Preparation of acidic aqueous colloidal solutz'on 0ymcr'hyl other ofmethylol melamine-- One hundredandsixty-eight parts of the 50% solutionas prepared immediately above, werestirred with 565 parts of water and109 parts of aceticaciol- (56%). The resulting-solution contained aboutof the methyl ether of methylol melamine condensation-product andabout7.3% of acetic acid. The solution was allowed to age for 6 hours at 85F. during which time it developed a bluish opalescent appearance and theparticles. of partially polymerized condensation product becamesubstantive to cotton fibers. The condensation product in this colloidalsolution was analyzed and was found to comprise-3:1 molsof-combinedformaldehyde per mol of melamine.

C. Treatment of all cotton; fabric. The, col-.

loidal solution as obtained above was. diluted with water until itcontained 6% of the partially polymerized condensation product.marquisette was then treatedwith this solution, dried, heated toinsolubilize the; condensation product andgwashed; using the identicalproce- The con- Av cotton- 19- dure. described in paragraph (1' ofExemplar; The resulting fabric had substantia lynthesan e dimensionalstability and crisp, stifi ened' finish, as the fabric producedaccording to the proce dure of Example I. V

In accordance with the; procedures her einbe- O T t' Gl fQ i i in. h dcri tion an x mpl s... it is, possible to fix on'the fabric dyestuffswhich normally bleed when the dyed-fabricis immersed in hot water, andalso obtain excellent shrinkage,

n ol nd a s p n n t f ne in The aboveprocedures can be modified asset-forth,

below in order to take'advantage of thesubstantivity of the colloidal,partially polymerized condensation product for oellulosic materials suchas cotton andregenerated;cellulose, particularly when-dye fixationis ofprimary importance,

carrying out this feature of the invention the fabric containingcel-lulosic yarns is first dyed; in the usual dyeing apparatus and isthentreated;

preferably. after the-dyed fabric has been rinsed and while it is stillwet, with from 5, to 70'times its own dry weight of the acidicaqueous-c01 loidal solution of the partially polymerized con densat-ionproduct, the condensation product.

being present in the solution in amounts of from 1 to 12% on the weightof the fabric.

of-the solution.

The fabric is allowed to remain in the solurtion or is alternatelyimmersed; in the solution and then removed therefrom until froinl to 10%of the condensation product is depositedthere on. During this step thecondensation product' because of its substantivity for cellulosicmaterials;-

migrates from the solution to the fabric; The,

amount of condensation product deposit ed;,on, the fabric is readilyascertained by testing;

samples of the fabric. It is. not necessary to obtain completeexhaustion. of the. condensation product, for. the desired add on can beobtained by adjusting" the concentration of the solutionused asrequired. The temperature of the. colloidal solution-hasv someinfluence. on the rate of exhaustion. Satisfactory results are obtainedif the solution is maintained'at tempera: tures. between about 20 and C.during the treatment. Temperatures of about 35 to '75. C.

are preferred. The treatment generally requires.

about 5 to 60 minutes depending on thetempera ture and concentration ofthesolution and theamount of condensation product which itis de.-. siredto exhaust on the fabric. The treatment may be carried outfor longerperiods of time, if desired, although there is no particular advan: tagein doingso in most instances.

After the desired amount of condensation prod-v uct has been exhaustedon the fabric, thefabric is rinsed with water and-dried. The fabric maytures, for example, to 240 F. Insolubiliza tion of the condensationproduct is not neces;

sary. or essential following, exhaustion, because.

the condensation product on the fabric, is re sistant towashingorlaundering without complete insolubilization.

The foregoing modification-of this invention is illustrated by thefollowing example;

Example VI An acid aqueous colloidal solution was first prepared asdescribed in paragraph B of Example I. This solution was diluted withwater until .it contained 0.2 by weightof the condense In most.instances, it is preferred totreat the-dyed fabric; with from 10 to 50%,based on its own dryweight,-

be air dried or dried at relatively low tempera--v V 11 tion product.solution were then used to treat 1 part of dyed cotton fabric accordingto the following procedure.

The cotton fabric was first dyed with Chlorantine Fast Red (Color IndexNo. 278) in a dye beck in the normal manner. The fabric was then rinsedwith water and while still wet was treated with the colloidal solutionof 0.27% concentration using 20 parts by weight of the solution to 1part by weight of the fabric on an air dry basis. The colloidal solutionwas heated to a temperature of 160 F. prior to the treatment of thefabric and maintained at that temperature during the treatment. Thefabric was agitated while in contact with the solution and wasmaintained in contact with the solution for a period of 15 minutes. Thefabric was then removed from the solution, rinsed with cold water andallowed to dry at room temperature (about 75 F.). The fabric containedapproximately 5% of the condensation product on the weight of thefabric.

The resulting fabric possessed a stiffened finish and good resistance todye bleeding. A piece of the same fabric dyed in the same manner but notafter-treated with a colloidal solution of the condensation productexhibited considerable bleeding when a 1 gram sample of the fabric wasimmersed in '75 cc. of cold water and then brought to the boil.

Various modifications and changes may be made in the processes of thisinvention as will be apparent to those skilled in the art to which theinvention appertains without departing from the spirit and intent of thepresent invention. Accordingly, it is intended that this invention belimited only by the scope of the appended claims.

What is claimed is:

1. A process of finishing a textile fabric containing at least 70% ofcellulose yarns which comprises wetting out said fabric in an acidicaqueous colloidal solution of from 1 to 12% by weight of a positivelycharged, partially polymerized methyl ether of methylol melaminecondensation product containing from 2.8 to 6 mols of combinedformaldehyde and from 2 to 6 mols of combined methanol per mol ofmelamine, said solution containing from 1.2 to 8.5% by weight,calculated on the basis of a 10% by weight solution of the condensationproduct, of a watersoluble organic acid selected from the groupconsisting of acetic acid, hydroxy-acetic acid and formic acid and beingfree of polyhydric alcohols; extracting the fabric to deposit from 1 to12% by weight, based on the weight of the fabric, of the condensationproduct, heating said fabric to a temperature between about 200 and 350F. to dry the fabric and insolubilize the condensation product, washingthe fabric to remove the acid therefrom and then drying said fabric.

2. The process of claim 1, wherein the organic acid is acetic acid andthe solution contains from 6 to 8.5% by weight of said acid calculatedon the basis of a 10% by weight solution of the condensation product.

3. The process of claim 1, wherein the organic acid is hydroxy-aceticacid and the solution contains from 6 to 8% by weight of said acidcalculated on the basis of a 10% by weight solution of the condensationproduct.

4. The process of claim 1, wherein the organic acid is formic acid andthe solution contains from 1.2 to 3% by weight of said acid calculatedTwenty parts by weight of this.

12 on the basis of a 10% by weight solution of the condensation product.

5. A process of finishing a dyed textile fabric containing at least 70%cellulose yarns which comprises immersing said fabric while it is stillWet from the dyeing operation in from 5 to '70 times its own dry weightof an acidic aqueous colloidal solution of from 1 to 12% by weight,based on the dry fabric weight, of a positively charged, partiallypolymerized methyl ether of methylol melamine condensation productcontaining from 2.8 to 6 mols of combined formaldehyde and from 2 to 6mols of combined methanol per mole of melamine, and from 1.2 to 8.5% byweight, calculated on the basis of a 10% by weight solution of thecondensation product, of a Water-soluble organic acid selected from thegroup consisting of acetic acid, hydroxy-acetic acid and formic acid,said solution being free of polyhydric alcohols, continuing theimmersion treatment until from 1 to 12% by weight of said condensationproduct, based on the fabric, has exhausted on the fabric, whereby saidcondensation product on the fabric is rendered wash resistant, rinsingthe fabric to remove acid therefrom and then drying said fabric.

6. The process of claim 5, wherein said organic acid is acetic acid andthe solution contains from 6 to 8.5% by weight of said acid, calculatedon the basis of a 10% solution of the condensation product.

7. The process of claim 5, wherein said organic acid is hydroxy-aceticacid and the solution contains from 6 to 8.5% by weight of said acid,calculatecl on the basis of a 10% solution of the condensation product.

8. The process of claim 5, wherein said organic acid is formic acid andthe solution contains from 1.2 to 3% by weight of said acid, calculatedon the basis of a 10% solution of the condensation product.

9. A process of finishing a fabric consisting of cellulose yarns whichcomprises wetting out said fabric in an acidic aqueous colloidalsolution of from 1 to 12% by weight of a positively charged, partiallypolymerized methyl ether of methylol melamine condensation productcontaining from 2.8 to 6 mols of combined formaldehyde and from 2 to 6mols of combined methanol per mol of melamine, said solution containingfrom 6.5 to 8% by weight of acetic acid calculated on the basis of a 10%by weight solution of the condensation product and being free ofpolyhydric alcohols, extracting said fabric to deposit from 2 to 9% byweight of the condensation product, based on the fabric, heating thefabric at temperatures of 225 to 300 F. to insolubilize saidcondensation product and then washing the fabric to remove acidtherefrom.

. 10. A process of finishing a fabric consisting of cellulose yarnswhich comprises wetting out said fabric in an acid aqueous colloidalsolution of from 1 to 12% by weight of a positively charged, partiallypolymerized methyl ether of methylol melamine condensation productcontaining from 2.3 to 6 mols of combined formaldehyde and from 2 to 6mols of combined methanol per mol of melamine, said solution containingfrom 7 to 8.5% by weight of hydroxyacetic acid calculated on the basisof a 10% by weight solution of the condensation product and being freeof polyhydric alcohols, extracting said fabric to deposit from 2 to 9%by weight of said condensation product, based on the fabric, heating thefabric at temperatures of 225 to 300 F. to insolubilize saidcondensation product, and thereafter washing the fabric to remove acidtherefrom.

11. A process of finishing a fabric consisting of cellulose yarns whichcomprises wetting out said fabric in an acidic aqueous colloidalsolution of a positively charged, partially polymerized methyl ether ofmethylol melamine condensation product containing from 2.8 to 6 mols ofcombined formaldehyde and from 2 to 6 mols of combined methanol per molof melamine, said solution containing from 1.4 to 2% by weight of formicacid calculated on the basis of a by weight solution of the condensationproduct and being free of polyhydric alcohols, extracting said fabric todeposit from 2 to 9% by weight of said condensation product, based onthe fabric, heating said fabric at temperatures of 225 to 300 F. toinsolubilize said condensation product and then washing the fabric toremove acid therefrom.

12. A process of finishing a textile fabric containing at least 70%cellulose yarns which comprises wetting out said fabric in an acidicaqueous colloidal solution of from 1 to 12% by weight of a positivelycharged, partially polymerized methyl ether of methylol melaminecondensation product containing from 2.8 to 6 mols of combinedformaldehyde and from 2 to 6 mols of combined methanol per mol ofmelamine, from 1 to 40% by weight, on the weight of said condensationproduct, of dispersed polyvinyl acetate and from 1.2 to 8.5% by weight,calculated on the basis of a 10% by weight solution of the condensationproduct, of a water-soluble organic acid selected from the groupconsisting of acetic acid, hydroxy-acetic acid and formic acid, saidsolution being free of polyhydric alcohols; extracting the fabric todeposit from 1 to 12% by weight of said condensation product, based onthe fabric, heating the fabric to a temperature between about 200 and350 F. to dry the fabric and insolubilize the condensation product,washing the fabric to remove the acid therefrom and drying the fabric.

13. A composition for treating cellulose textile fabrics which containat least 70% of cellulose yarns comprising essentially a mixture of anacidic aqueous colloidal solution of a positive- 1y charged, partiallypolymerized methyl ether of methylol melamine condensation productcontaining from 2.8 to 6 mols of combined formaldehyde and from 2 to 6mols of combined methanol per mol of melamine, from 1 to by weight. onthe weight of said condensation product, of dispersed polyvinyl acetateand from 1.2 to 8.5% by weight, calculated on the basis of a 10% byweight solution of the condensation product, of a water-soluble organicacid selected from the group consisting of acetic acid, hydroxy-aceticacid and formic acid, said composition being free of polyhydricalcohols.

14. A process of finishing a textile fabric containing at least ofcellulose yarns which comprises wetting out said fabric with an acidicaqueous colloidial solution of a positively charged, partiallypolymerized methyl ether of methylol melamine condensation productcontaining from 2.8 to. 6 mols of combined formaldehyde and from 2 to 6mols of combined methanol per mol of melamine, said solution containingfrom about 1.2 to 8.5% by weight, calculated on the basis of a 10% byweight solution of the condensation product, of a water-soluble acidselected from the group consisting of acetic acid, hydroxyacetic acidand formic acid and being free of polyhydric alcohols, allowing from 1to 12% by weight of said condensation product, based on the weight ofthe fabric, to deposit on said fabric, heating the fabric toinsolubilize the condensation prod uct sufficiently to make it resistantto removal by washing, washing the fabric to remove acid therefrom anddrying said fabric.

ICERN E. FO-LKERS.

References Cited in the file of this patent UNITED STATES PATENTSFOREIGN PATENTS Country Date Great Britain May 30, 1938 Great BritainDec. 8, 1948 Number Number

13. A COMPOSITION FOR TREATING CELLULOSE TEXTILE FABRICS WHICH CONTAINAT LEAST 70% OF CELLULOSE YARNS COMPRISING ESSENTIALLY A MIXTURE OF ANACIDIC AQUEOUS COLLOIDAL SOLUTION OF A POSITIVELY CHARGED, PARTIALLYPOLYMERIZED METHYL ETHER OF METHYLOL MELAMINE CONDENSATION PRODUCTCONTAINING FROM 2.8 TO 6 MOLS OF COMBINED FORMALDEHYDE AND FROM 2 TO 6MOLS OF COMBINED METHANOL PER MOL OF MELAMINE, FROM 1 TO 40% BY WEIGHTON THE WEIGHT OF SAID COMDENSATION PRODUCT, OF DISPERSED POLYVINYLACETATE AND FROM 1.2 TO 8.5% BY WEIGHT, CALCULATED ON THE BASIS OF A 10%BY WEIGHT SOLUTION OF THE CONDENSATION PRODUCT, OF A WATER-SOLUBLEORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF ACETIC ACID,HYDROXY-ACETIC ACID AND FORMIC ACID, SAID COMPOSITION BEING FREE OFPOLYHYDRIC ALCOHOLS.
 14. A PROCESS OF FINISHING A TEXTILE FABRICCONTAINING AT LEAST 70 OF CELLULOSE YARNS WHICH COMPRISES WETTING OUTSAID FABRIC WITH AN ACID AQUEOUS COLLOIDAL SOLUTION OF A POSITIVELYCHARGED, PARTIALLY POLYMERIZED METHYL ETHER OF METHYLOL MELAMINECONDENSATION PRODUCT CONTAINING FROM 2.8 TO 6 MOLS OF COMBINEDFORMALDEHYDE AND FROM 2 TO 6 MOLS OF COMBINED METHANOL PER MOL OFMELAMINE, SAID SOLUTION CONTAINING FROM ABOUT 1.2 TO 8.5% BY WEIGHT,CALCULATED ON THE BASIS OF A 10% BY WEIGHT SOLUTION OF THE CONDENSATIONPRODUCT, OF A WATER-SOLUBLE ACID SELECTED FROM THE GROUP CONSISTING OFACETIC ACID, HYDROXYACETIC ACID AND FORMIC ACID AND BEING FREE OFPOLYHYDRIC ALCOHOLS, ALLOWING FROM 1 TO 12% BY WEIGHT OF SAIDCONDENSATION PRODUCT, BASED ON THE WEIGHT OF THE FARBIC, TO DEPOSIT ONSAID FABRIC, HEATING THE FABRIC TO INSOLUBLIZE THE CONDENSATION PRODUCTSUFFICIENTLY TO MAKE IT RESISTANT TO REMOVAL BY WASHING, WASHING THEFARBIC TO REMOVE ACID THEREFROM AND DRYING SAID FARBIC.